Magnetic softness of permalloy granular films produced by Co-evaporation

Permalloy granular films were fabricated by co-evaporation. In this paper, MgF₂ and CaF₂ are used as matrices. The films exhibit good magnetic softness and perpendicular or inplane uniaxial anisotropy that determines high frequency characteristics. The anisotropy is considered to originate from alignment of nanosized granules connected with exchange interaction. Magnetization curves, susceptibility and transmission electron microscopic images support speculation of microscopic granular structure and origin of anisotropy. Very high deposition speed is possible without serious deterioration of magnetic softness. High controllability of anisotropy and high speed deposition are advantageous from the industrial standpoint.